The atmosphere in and around textile and related facilities may often carry undesirable particles of dust, fibers and lint. To remove, and in some instances recover, at least a portion of these particles, the air in such facilities must be continuously filtered. Various machines and methods have been designed to eliminate particles of this type from the carrier air in and around such facilities.
One such machine is the commercially available Fibr-A-Filter.RTM. air filtering system sold by the Continental Conveyor and Equipment Company, Inc.. This machine is a primary filter designed to remove and recover fibers and lint from the carrier air in and around textile facilities and to a lesser extent, dust, which may become entrapped within the fibers or lint being removed and recovered from the carrier air. The machine is described in U.S. Pat. No. 4,325,717 to Crowley. Other examples of primary filters are described in U.S. Pat. No. 1,649,220 to Goodloe and in U.S. Pat. No. 3,525,198 to Neitzel. In such primary filters, the larger particles of fibers and lint from the particle-carrying atmosphere being filtered are deposited on the exterior surface of a rotating drum whereafter they can be removed and recovered as bat. A portion of the smaller, undesirable particles, finer dust particles and the like, can move through the rotating drum surface to interior of the drum and be removed from the air filtering machinery for further filtration in a secondary filter. However, a portion of these smaller particles will become entrained in the bat and will be removed therewith.
One example of a secondary filter is the commercially available Intr-A-Vac.RTM. air filtering system sold by the Continental Conveyor and Equipment Company, Inc. Other examples of secondary filters are disclosed in U.S. Pat. No. 3,887,344 to Smith; in U.S. Pat. No. 3,757,496 to Berg; and in United Kingdom Pat. No. 16,392 to Samuleson. In these secondary filters, a cylindrical surface is provided with an interior fur-line covering constituting the filtering media. The air to be filtered is moved to within the interior of the cylindrical surface and through the filtering media to exterior of the surface. The dust particles are then entrapped within the filtering media and the clean air can be vented to exterior of the machinery. A vacuum system within the cylindrical surface is rotated with respect to the cylindrical surface for vacuuming the dust therefrom. This dust ladened air from the vacuum system is moved either to an appropriate settling-type air cleaner or recirculated back into the primary filter for further filtration.
In all of these devices, either primary or secondary filters, an air flow of a first pressure enters the machine and leaves at a second pressure. Further, in all of the devices, movement of mechanical parts occurs between the filtering surface and a debris-removing mechanism.
All air filtering machinery of this type are thus adapted to utilize apparatus for controlling the air filtering machinery as a function of the nature and pressure of the air being filtered.